In a tire air or pneumatic pressure monitoring device described in Japanese Patent Application Publication No. 2010-122023, TPMS (tire pressure monitoring system) data is transmitted at a time at which an acceleration in a rotational direction of a TPMS sensor installed on each wheel reaches “1” [G] or “−1” [G] so that a TPMS sensor transmits the TPMS data at a constant rotational position of a wheel. A TPMS control unit installed on a side of a vehicle body determines a wheel position of the TPMS sensor based on the number of teeth that are acquired from a chain of wheel speed pulses detected by a wheel speed sensor at a timing at which the TPMS data has been received.
However, in this conventional technique, in order to detect that the TPMS sensor has reached a predetermined rotational position, it is necessary to shorten the sampling period or cycle. Thus, there has been a problem of difficulty in extending a lifetime of a battery of the TPMS sensor (tire air pressure transmission device).